How do you change chain case oil on ski doo xp?

To change the chain case oil on a Ski-Doo XP, first, ensure the snowmobile is on a level surface and the engine is cool. Remove the drain plug from the chain case and allow the old oil to fully drain out. Once drained, replace the plug and use a funnel to fill the chain case with new oil, typically to the specified level indicated in the owner's manual. Finally, check for leaks and ensure the oil is at the correct level before using the snowmobile.